Fuze with clockworks



Oct. 1, 1957 N. E. G. MULLER 2980,@01

FuzE wrm cLocKwoRxs' Filed Feb. 1o. 195s FUZE WITH CLOCKWORKS Nils Erik Gustaf Kiiller, Karlskoga, Sweden, assignor to Aktiebolaget Bofors, Bofors, Sweden, a corporation of Sweden Application February 10, 1953, Serial No. 336,179 Claims priority, application Sweden March 26, 1952 8 Claims. (Cl. 102-84) The present invention refers to a fuze containing a releasing device for actuation of the fuze by outside iniluences, a clockwork, started by the said device, and a fnac-setting device to adjust the clockwork at a certain tripping time. A projectile provided with a fuze of the said kind is used very much when firing from one medium to another, i. e. from air to water. TheV clockwork is then usually adjusted in such a way that it initiates the projectile at a certain time, which can be set before the clockwork is started. The clockwork is started by means of the releasing device of the fuze. This will occur when the projectile reaches the second medium. The projectile will thus be initiated after a certain time, corresponding to the time for which the clockwork is set. During this time the projectile will have passed a4 certain distance in the second medium. If a curve is drawn over the differently set times at the clockwork and the corresponding distances passed in the second medium, it is shown that the curve will have the form of a parabola. However, it has proved nearly quite imposible to create a clockwork, which after having been set for a certain time also initiates theY projectile at this time. As a rule the clockwork goes a time a little shorter or a little longer than the time wanted. Thus, it must be counted upon that a projectile can pass a shorter or a longer distance than desired in 'the second medium. if the said curve is studied, it is found that the difference in distance for a certain time erro-r will be considerably greater in the beginning than in the end of the trajectory of the projectile in the second medium. This is a veryv great disadvantage.

rThe purpose of the present invention is to avoid the said disadvantage by providing the fuze of the projectile with two clockworks, one of which is to work mainly during the rst part of the trajectory of the projectile in the second medium while the other clockwork is to function during the other part of the trajectory of the projectile.

A fuze containing a releasing device for'actuation of the fuze by outside influences, a clockwork and a fuzesetting device setting the clockwork at a certain tripping time, which releasing device when actuated starts the said clockwork, is characterized according to the present invention by a second clockwork, which is started at the same time as the first-mentioned clockwork, and the tripping time of which is adjustable by the said fuzesetting device and bythe two clockworks being made in sucha way that during a certain predetermined time interval, counted from the starting of the clockworks, only one clockwork can release and that after the said time-interval only the second clockwork can be released.

The present invention will be described more indetail in connection with the enclosed drawing, which shows a fuze according to the present invention.

A in the ligure, 1 is a nose-shaped member which has the form of a cap. The lower edge of the nose 1 rests against a ange ring 2, arranged at a cylindrical tube,

' is conical.

VAPatented Oct. 1, 1957 ice consisting of the two parts 3 and 4. The upper end of the tube 4 is covered by a member 5. From the upper side of the member 5 two cylindrical tubes 6 and 7 run. The parts 3 `and 4--7 can be made of a single piece and connected with each other. The member 5 is provided with a through hole 8 in the middle. The external surfaces of the parts 4, 5, and 7, together with the internal surface of the nose 1, form a chamber. A channel 9 runs from the top of the nose 1 to the said chamber. It is, of course, also possible to replace this channel by a number of channels with smaller cross sections. In the upper end of the channel 9, a groove 10 is made. This groove is intended for a protective plate which can easily be removed. It is also possible to use a plug provided with threads instead of a protective plate. The groove 10 must then be replaced by threads. From the lower part of the outer wall of the nose 1, a channel 11 runs to the chamber. This channel has been given such a direction that a medium flowing against the nose 1 in an axial direction in relation to the symmetry axis of the nose shall not be able to flow through the channel 11. Also here it is possible to use a number of channels of the same character as the channel 11. At its upper end the tube 7 is provided with internal threads and a flange. A sealing plate rests against the said flange, which plate, for example, can be made of Phosphor bronze. The plate has Ibeen given' the reference number 12. The said plate is kept pressed against the flange by means of a plate 13, which is provided with threads to fit into the threads mentioned before, and which is screwed into the upper end of the tube 7. The plate 13 is provided with a number of through holes, two of which are visible in the ligure and have been given the reference numbers 14 and 15. In the hole 8 there is a bar V16, which is kept in a predetermined position by a pin 17 going through the bar and the member 5. In its upper part, the bar 16 is provided with a member 18, the surface of which This surface is intended to engage into a second conical surface, which is arranged at a liner 19 at the internal surface of the tube 6. The liner 19 can be made of lead or some other material with similar properties. Instead of using the liner 19, it is possible to give the internal surface of the tube 6 the sameshape as the said conical surface of the liner 19.` At the member 18 there is fastened a circular plate 20, with fa diameter nearly the same as the internal diameter of the tube 7. The cylindrical part 4 of the tube is centered in relation to the nose-shaped member 1 and fastened axially by a screw 21, which goes through a hole 22 of' the nose-shaped member 1 and to a peripheral groove 23, arranged in `the part 4. The parts 3 and 4 are fastened by means of one or several screws 24. The nose 1 with the cylindrical parts 3 and 4 of the tube are put into and fastened in casing 25, which in its bottom is provided with a flange plate 26 and a hole 27. in its lower part the bar 16 is provided with a stop device 28. Against this device the ends of two arms 29 and 30 rest. The other ends of the arms 29 and 30 are fastened to the upper ends of thejbars 31 and 32. In the upper ends the bars 31 and 32 are rotatably supported in the holes 33 and 34 of the member 5. In the lower ends, the bars 31 and 32 are preferably supported in a bracket or the like, provided with holes, or in some other suitable way. Around each of the bars 31 and 32 there is a spring 35 and 36, respectively. The springs 35 and 36 have their upper ends connected with the arm's 29 and 30, respectively. The lower ends of the springs 35 and 36 are closely connected with the tube part 3. At the building-up, the

springs are arranged in such a way that they aimto turn the arms 29 and 30, respectively, against the stop device 28; In its lower end the arm 31 and the arm 32, re

iclockworks 41 and 42. land 44 are arranged above the pointer-shaped devices,

Y water.

spectively, is provided with an arm 37 and an arm 38, respectively. The arms 37 and 38 rest against pointershaped devices 39 and 40, which can be turned by the Hollow cylindrical devices 43 which cylindrical devices in the bottoms are provided each with a recess of the same form as the pointer-shaped devices 39 and 40. One ofy the said devices is shown in the` figure. It has been given the reference number 45. The pointer-shaped devices can snap into the said recesses. When snapping in, the fuze tops 46 and 47 of the clockworks are released. When released the top 46 and the top 47, respectively, contact a detonator 48 and 49, respectively, in a charge 50 and 51, respectively. The cylindrical device 43 and 44, respectively, is in close contact with the shaft 552 and 53, respectively. The shafts 52 and 573 are in their Yupper ends provided with gears 54 and 55. The two gears 54 and 55 are in mesh with a gear 56, which is placed on the output shaft 57 of a synchro element 53. This element contains stator and rotor windings and can be fed electrical voltages by means of the cable 59 in such a way that the position of the shaft can be rotated to adjust the angular position of the recesses 45 relative to the startingpositions of the hands 3i?, 40, thereby to set controllably the fuze to be actuated a predetermined period of time following the initiation of the timing mechanism.

The device described above functions as follows. It is presumed that the device shown in the figure is fastened to a projectile moving from one medium to another, i. e. from air to water, and that the protecting plate in the groove 10 has been removed just before tiring. During the movement of the projectile in the air, there will always be air in the chamber formed by the internal wall of the nose 1 and the external wall of the parts 4, 5, and 7.k

When the projectile enters another medium, the air of the chamber will be pressed out through the channel 11 by the last-mentioned medium, which is presumed to be In order to press down the plate 20 with the parts 16 and 18, it is necessary that the medium actuates the plate 20 through the holes 14 and 15 by means of the tightly tting plate 12 with a power exceeding the power required to shear off the pin 17. When this power is reached, the pin 17 is sheared off, and the plate 20 with the parts 16 and 18 are brought down by the mediumat the same time as the tightly tting plate 12 is destroyed. In order to prevent the medium from penetrating into the projectile through the hole 8, the parts- 18 and 19 are provided with conical surfaces. The two parts will adhere to each other when the plate 20 is pressed down by the water and are locked in this position. One of the two conical surfaces can be of such a material that the two conical surfaces lie close to each other. It has then proved suitable that one surface iS made of lead or some other material with the same or nearly the same properties. When the bar 16 has obtained a new position, the two arms 29 and 30 will move inwards, which means that the contact of the arms 37 and 38 with the pointer-shaped devices 39 and 40 will cease. While the two clockworks 41 and 42 will start at the same time, one clockwork, i. e. the clockwork 41 is set to go faster than the second clockwork 42. The two pointer-shaped devices of the clockwork can then snap into the recesses of the members 43 and 44 after a certain time interval, depending on what position the members 43 and 44 have been given by the synchro element 58. As it is sucient if only one of the clockworks is released, it is arranged in such a way that during a certain predetermined time interval from the moment the clockworks have been started, only the pointer-shaped device of the fast clockwork is permitted to snap in, while after the said time interval only the pointer-shaped de-V vice of the slow clockwork is allowed to snap in. At

the snapping in, either detonator 48 or 49 will be ignited,

whereafter either charge S or 51 will be ignited.

I claim:

Y l. A fuse for an explosive projectile designed for a trajectory successively traversing a gaseous medium and a liquid medium, said fuse comprising a detonating means, a first and a second clockwork each individually coacting with said detonating means and independently tripping said detonating means within a predetermined period of time, the rst clockwork having a tripping period shorter than the second clockwork, setting means coacting with said clockworks to set the latter for tripping the detonating means by either of the clockworks at the end of a predetermined interval of time after release of the clockworks, whereby the detonating means are tripped by the Vfirst clockwork at the end of a time interval ending Within the shorter tripping period thereof and by the second clockwork at the end of a time interval ending within the remainder of the longer tripping period of the second clockwork.

2. A fuse according to claim l, wherein said tirst clockwork is faster than the second clockwork whereby the first clockwork is the more sensitive one.

3. A fuse according to claim l and further comprising a tripping means for each of said clockworks, each of said tripping means including two coacting members movable relative Vto each other by the operation of the respective clockwork and engageable with each other when the respective clockwork has completed its tripping period, engagement of said'members eiecting tripping of the detonating means.

4. A fuse according to claim`3, wherein one member of each pair of coacting members is formed with a recess and the other member of each pair is rotatable by the respective clockwork for engagement with said recess when in registry therewith upon completion of the tripping period of the respective clockwork, the said other member tripping the detonator means when in said recess, and wherein means are provided for urging the two membersV of each pair into engagement in said position of registry.

5. A fuse according to claim l, wherein the said setting means comprise a remote controlled rotary synchro means having a rotor engaging a component of each clockwork controlling the tripping period of the respective clockwork lforV jointly adjusting said components to vary said time interval by altering the angular position of said rotor while maintaining the aforesaid ratio of the tripping periods of the clockworks.

6. A fuse for an explosive projectile designed for a trajectory successively traversing a gaseous medium and a liquid medium, said fuse comprising a detonating means, a first and a second clockwork each individually coactingV with said detonating means and independently tripping said detonating means within a predetermined period of time, the rst clockwork having a tripping period shorter than the second clockwork, setting means coacting with `said clockworks to set the latter for tripping the detonating means by either of the clockworks at the end of a predetermined interval of time after release of the clockworks, whereby the detonating means are tripped by the rst clockwork at the end of a time interval ending within the shorter tripping period thereof by the second clockwork at the end of a time interval ending within the remainder of the longer tripping period of the second clockwork, stop means arresting both said clockworks, release means operable by impact when said projectile contacts the liquid medium and coacting with said stop means for simultaneously releasing both said clockworks upon operation of the release means.

7. A fuse according to claim 6, wherein the said release means comprise an actuating member movable from 5 position and released for the purpose aforesaid upon clockworks upon movement ofthe actuating member into movement of the actuating member into its second posiits second position.

tion. l

8. A fuse according to claim 7, wherein the said lock- References Cited in the l 0f this patent ing means further comprise two spring loaded rotary bars 5 each supporting one of the aforesaid locking elements FOREIGN PATENTS and a second 1ocking element engaging a component of 285,553 Great Britain Feb. 16, 1928 the respective clockwork for arresting the latter when the 396,171 Great Britain Aug. 3, 1933 actuating member is in its initial position and releasing 379,944 Italy Apr. 15, 1940 the said component for simultaneously starting both the l0 

